Over the past years, recreational boating has become an important and often-engaged-in pastime of many people throughout the world. Depending upon the ability to make a significant investment, participants in this pastime can either rent or purchase a boat for use for waterskiing and other water activities.
For those who purchase their own boat, a number of choices are available to them. One of the choices is whether to buy a boat employing an inboard motor or an outboard motor. Again, the ability to make financial outlays appears to be the key factor entering into the decision.
The former type of power configuration is one wherein the motor is a permanent fixture of the craft of which it is a part. The latter configuration employs a detachable motor securable to the transom or stern sheet of the boat. Various types of securing means can be and are employed for effecting mounting of the motor. Typically, mounting is effected by engaging a member of a motor-mounting rack with the outwardly facing surface of the transom. An arm extends over the transom and inboard thereof. The arm carries a screw-down type clamp which can be manipulated to be brought into engagement with the inwardly facing side of the transom. Appropriate pressure can be applied to the screw-down type clamp to securely hold the motor in place.
An outboard motor is, typically, disposed for pivoting about an axis defined by a shaft of the mounting rack. Such pivotal mounting allows the motor to be tilted upwardly when, for example, the boat to which it is mounted is taken out of the water and is to be transported on a trailer. Such tilting involves fairly significant angular changes.
Another purpose in mounting an outboard motor pivotally with respect to the transom of the craft with which it is to be used is to enable "trimming" of the motor. Trimming is a process by which fine angular adjustments are made to the motor while the propeller is in the water in order to maximize the efficiency of operation of the motor. The static and dynamic positioning of a motor will vary depending upon the length of the craft, its center of gravity, etc. As can be seen, therefore, when an outboard motor is used with different water vehicles, it will have to be trimmed differently.
Manufacturers of outboard motors typically provide structure to allow trimming of the motor depending upon the craft with which it is to be used. Most frequently, this structure comprises an arcuate bracket extending rearwardly and upwardly from a location on the motor-mounting rack. The bracket has, formed therein, a plurality of arcuately spaced apertures. The motor itself can be provided with an aperture registrable with each of those formed in the bracket. Depending upon the desired location of the motor with respect to the bracket, the aperture of the motor can be brought into registration with a desired aperture in the bracket. A pin can, thereafter, be inserted to maintain the desired motor orientation.
While motor manufacturers typically employ the trim method described hereinbefore, various companies have devised "tilt and trim" devices to accomplish both drastic changes in angle of tilt of the motor and to finely trim the angle of the motor when it is in the water. A number of these devices employ hydraulic or pneumatic cylinders utilizing a reciprocable piston. The base of the cylinder is mounted to the transom of the boat with which the motor is used, and the distal end of the telescoping portion is affixed at the motor. By selectively extending and retracting the piston, the motor is tilted about the axis with respect to which it pivots. As can be seen, such a device enables both large and small angular changes to be made to the relative positioning of the motor with respect to the transom.
A problem that can be encountered during boating activity is one wherein the downwardly depending motor encounters submerged debris or a shallow bottom. When such an occurrence takes place, it is desirable that the motor be automatically pivoted upwardly and rearwardly with respect to the transom. This is so for a number of reasons. First, if the motor remained in place relative to the boat, the hydrodynamic characteristics of the boat could become drastically altered. Second, by allowing the motor to so pivot, the likelihood of serious damage being occasioned upon the motor is minimized.
Prior art structures have sought to deal with this problem. Virtually universally, however, the focus of the solution has been providing a hydraulic or pneumatic bypass to permit pivoting when a sudden increase in pressure is brought to bear upon the motor. As a result, when the motor is pivoted because of engagement with submerged debris or a shallow bottom, the mechanism often need be reset before continuing normal craft operation. Certainly, a device both simple in operation and automatically resetable after the motor is pivoted upwardly would be a significant advance in the art.
The present invention is one which addresses the problems of the prior art, provides solutions to those problems, and accommodates the desirable features dictated by the art. It is a simple-operating and exclusively-mechanical "tilt and trim" mechanism significantly improved over structures of the prior art.